Tokimeki Tonight: Etō Mōri no Kakeochi

This is a long, epic manga that spans three generations of the Etou family. The first part is about Ranze, a relatively normal high school girl, except for the fact that her father is a vampire, her mother is a werewolf, and that she has magical powers of her own. Her family was banished from the Magic World to live among the humans, and they now guard the gate between the two realms. The story really begin when Ranze falls for a human boy, which her parents strictly forbid. Later story arcs focus on Ranze's brother and on Ranze's daughter. 

(Source: Anime News Network) 

*Note: Includes 9 extra chapters.*